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id="post-meta"><div class="meta-firstline"><span class="post-meta-date"><i class="far fa-calendar-alt fa-fw post-meta-icon"></i><span class="post-meta-label">发表于</span><time class="post-meta-date-created" datetime="2025-06-04T10:30:00.000Z" title="发表于 2025-06-04 18:30:00">2025-06-04</time><span class="post-meta-separator">|</span><i class="fas fa-history fa-fw post-meta-icon"></i><span class="post-meta-label">更新于</span><time class="post-meta-date-updated" datetime="2025-06-04T10:30:00.000Z" title="更新于 2025-06-04 18:30:00">2025-06-04</time></span><span class="post-meta-categories"><span class="post-meta-separator">|</span><i class="fas fa-inbox fa-fw post-meta-icon"></i><a class="post-meta-categories" href="/categories/C-%E8%BF%9B%E9%98%B6/">C++进阶</a></span></div><div class="meta-secondline"><span class="post-meta-separator">|</span><span class="post-meta-wordcount"><i class="far fa-file-word fa-fw post-meta-icon"></i><span class="post-meta-label">总字数:</span><span class="word-count">2596</span><span class="post-meta-separator">|</span><i class="far fa-clock fa-fw post-meta-icon"></i><span class="post-meta-label">阅读时长:</span><span>10分钟</span></span><span class="post-meta-separator">|</span><span class="post-meta-pv-cv" id="" data-flag-title=""><i class="far fa-eye fa-fw post-meta-icon"></i><span class="post-meta-label">浏览量:</span><span id="busuanzi_value_page_pv"><i class="fa-solid fa-spinner fa-spin"></i></span></span></div></div></div></header><main class="layout" id="content-inner"><div id="post"><article class="container post-content" id="article-container"><div id="post-outdate-notice" data="{&quot;limitDay&quot;:365,&quot;messagePrev&quot;:&quot;It has been&quot;,&quot;messageNext&quot;:&quot;days since the last update, the content of the article may be outdated.&quot;,&quot;postUpdate&quot;:&quot;2025-06-04 18:30:00&quot;}" hidden></div><p>智能指针是 <code>C++</code> 中用于自动管理动态内存的类模板，它通过 <code>RAII</code>（资源获取即初始化）技术避免手动 <code>new</code> &#x2F; <code>delete</code> 操作，从而显著减少内存泄漏和悬空指针的风险</p>
<h1 id="为什么需要智能指针？"><a href="#为什么需要智能指针？" class="headerlink" title="为什么需要智能指针？"></a>为什么需要智能指针？</h1><figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br></pre></td><td class="code"><pre><span class="line"><span class="function"><span class="type">int</span> <span class="title">div</span><span class="params">()</span></span></span><br><span class="line"><span class="function"></span>&#123;</span><br><span class="line">	<span class="type">int</span> a, b;</span><br><span class="line">	cin &gt;&gt; a &gt;&gt; b;</span><br><span class="line">	<span class="keyword">if</span> (b == <span class="number">0</span>)</span><br><span class="line">		<span class="keyword">throw</span> <span class="built_in">invalid_argument</span>(<span class="string">&quot;除0错误&quot;</span>);</span><br><span class="line">	<span class="keyword">return</span> a / b;</span><br><span class="line">&#125;</span><br><span class="line"></span><br><span class="line"><span class="function"><span class="type">void</span> <span class="title">Func</span><span class="params">()</span></span></span><br><span class="line"><span class="function"></span>&#123;</span><br><span class="line">	<span class="type">int</span>* p1 = <span class="keyword">new</span> <span class="type">int</span>;</span><br><span class="line">	<span class="type">int</span>* p2 = <span class="keyword">new</span> <span class="type">int</span>;</span><br><span class="line">	cout &lt;&lt; <span class="built_in">div</span>() &lt;&lt; endl;</span><br><span class="line">	<span class="keyword">delete</span> p1;</span><br><span class="line">	<span class="keyword">delete</span> p2;</span><br><span class="line">&#125;</span><br><span class="line"></span><br><span class="line"><span class="function"><span class="type">int</span> <span class="title">main</span><span class="params">()</span></span></span><br><span class="line"><span class="function"></span>&#123;</span><br><span class="line">	<span class="keyword">try</span></span><br><span class="line">	&#123;</span><br><span class="line">		<span class="built_in">Func</span>();</span><br><span class="line">	&#125;</span><br><span class="line">	<span class="built_in">catch</span> (exception&amp; e)</span><br><span class="line">	&#123;</span><br><span class="line">		cout &lt;&lt; e.<span class="built_in">what</span>() &lt;&lt; endl;</span><br><span class="line">	&#125;</span><br><span class="line">	<span class="keyword">return</span> <span class="number">0</span>;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>
<p>如果 <code>p1</code> 这里 <code>new</code> 抛异常会如何？</p>
<blockquote>
<p><code>p1</code> 未成功分配，值为 <code>nullptr</code><br>函数直接跳转到 <code>catch</code> 块，<code>p2</code> 未分配，无内存泄漏</p>
</blockquote>
<p>如果 <code>p2</code> 这里 <code>new</code> 抛异常会如何？</p>
<blockquote>
<p><code>p1</code> 已分配但未释放，导致内存泄漏<br>函数跳转到 <code>catch</code> 块，<code>p2</code> 未分配，<code>delete p1</code> 和 <code>delete p2</code> 均未执行</p>
</blockquote>
<p>如果 <code>div</code> 调用这里又会抛异常会如何？</p>
<blockquote>
<p><code>p1</code> 和 <code>p2</code> 均已分配但未释放，导致双重内存泄漏<br>函数跳转到 <code>catch</code> 块，打印错误信息（如 “除 <code>0</code> 错误”）</p>
</blockquote>
<p><code>C++</code> 不像 <code>java</code> 具有垃圾回收机制，能够自动回收开辟的空间，需要自行手动管理，但是自己管理有时又太麻烦了，况且这里只是两个指针就产生了这么多问题，因此在 <code>C++11</code> 就推出了智能指针用于自动管理内存</p>
<h1 id="智能指针原理"><a href="#智能指针原理" class="headerlink" title="智能指针原理"></a>智能指针原理</h1><h2 id="RAll"><a href="#RAll" class="headerlink" title="RAll"></a>RAll</h2><figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">template</span>&lt;<span class="keyword">class</span> <span class="title class_">T</span>&gt;</span><br><span class="line"><span class="keyword">class</span> <span class="title class_">SmartPtr</span> </span><br><span class="line">&#123;</span><br><span class="line"><span class="keyword">public</span>:</span><br><span class="line">	<span class="built_in">SmartPtr</span>(T* ptr = <span class="literal">nullptr</span>)</span><br><span class="line">		: _ptr(ptr)</span><br><span class="line">	&#123;&#125;</span><br><span class="line">	</span><br><span class="line">	~<span class="built_in">SmartPtr</span>()</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="keyword">if</span> (_ptr)</span><br><span class="line">			<span class="keyword">delete</span> _ptr;</span><br><span class="line">	&#125;</span><br><span class="line"></span><br><span class="line"><span class="keyword">private</span>:</span><br><span class="line">	T* _ptr;</span><br><span class="line">&#125;;</span><br><span class="line"></span><br><span class="line"><span class="function"><span class="type">int</span> <span class="title">main</span><span class="params">()</span></span></span><br><span class="line"><span class="function"></span>&#123;</span><br><span class="line">	<span class="function">SmartPtr&lt;<span class="type">int</span>&gt; <span class="title">sp1</span><span class="params">(<span class="keyword">new</span> <span class="type">int</span>(<span class="number">1</span>))</span></span>;</span><br><span class="line">	<span class="function">SmartPtr&lt;string&gt; <span class="title">sp2</span><span class="params">(<span class="keyword">new</span> string(<span class="string">&quot;xxx&quot;</span>))</span></span>;</span><br><span class="line">	<span class="keyword">return</span> <span class="number">0</span>;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>

<p><code>RAII</code>（<code>Resource Acquisition Is Initialization</code>）是一种利用对象生命周期来控制程序资源（如内存、文件句柄、网络连接、互斥量等等）的简单技术</p>
<p>简单来说，就是把创建的对象给到 <code>SmartPtr</code> 类来管理，当对象的生命周期结束的时候，刚好类也会自动调用析构函数进行内存释放</p>
<p><strong>这种做法有两大好处：</strong></p>
<ul>
<li>不需要显式地释放资源</li>
<li>采用这种方式，对象所需的资源在其生命期内始终保持有效</li>
</ul>
<h2 id="像指针一样使用"><a href="#像指针一样使用" class="headerlink" title="像指针一样使用"></a>像指针一样使用</h2><p>都叫做智能指针了，那肯定是可以当作指针一样使用了，指针可以解引用，也可<br>以通过 <code>-&gt;</code> 去访问所指空间中的内容，因此类中还得需要将 <code>*</code> 、<code>-&gt;</code> 重载下，才可让其像指针一样去使用</p>
<figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">template</span>&lt;<span class="keyword">class</span> <span class="title class_">T</span>&gt;</span><br><span class="line"><span class="keyword">class</span> <span class="title class_">SmartPtr</span></span><br><span class="line">&#123;</span><br><span class="line"><span class="keyword">public</span>:</span><br><span class="line">	<span class="built_in">SmartPtr</span>(T* ptr)</span><br><span class="line">		:_ptr(ptr)</span><br><span class="line">	&#123;&#125;</span><br><span class="line"></span><br><span class="line">	~<span class="built_in">SmartPtr</span>()</span><br><span class="line">	&#123;</span><br><span class="line">		cout &lt;&lt; <span class="string">&quot;delete:&quot;</span> &lt;&lt; _ptr &lt;&lt; endl;</span><br><span class="line">		<span class="keyword">delete</span> _ptr;</span><br><span class="line">	&#125;</span><br><span class="line"></span><br><span class="line">	T&amp; <span class="keyword">operator</span>*()</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="keyword">return</span> *_ptr;</span><br><span class="line">	&#125;</span><br><span class="line"></span><br><span class="line">	T* <span class="keyword">operator</span>-&gt;()</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="keyword">return</span> _ptr;</span><br><span class="line">	&#125;</span><br><span class="line"><span class="keyword">private</span>:</span><br><span class="line">	T* _ptr;</span><br><span class="line">&#125;;</span><br></pre></td></tr></table></figure>

<p><code>*</code> 重载返回对象，<code>-&gt;</code> 重载返回地址，这部分的知识点在迭代器底层分析已经讲过很多遍了，就不过多叙述了，可自行翻阅前文</p>
<h1 id="C-11的智能指针"><a href="#C-11的智能指针" class="headerlink" title="C++11的智能指针"></a>C++11的智能指针</h1><p>智能指针一般放在 <code>&lt;memery&gt;</code> 文件里，<code>C++11</code> 也参考了第三方库 <code>boost</code></p>
<ol>
<li><code>C++ 98</code> 中产生了第一个智能指针 <code>auto_ptr</code></li>
<li><code>C++ boost</code> 给出了更实用的 <code>scoped_ptr</code> 和 <code>shared_ptr</code> 和 <code>weak_ptr</code></li>
<li><code>C++ TR1</code>，引入了 <code>shared_ptr</code> 等。不过注意的是 <code>TR1</code> 并不是标准版</li>
<li><code>C++ 11</code>，引入了 <code>unique_ptr</code> 和 <code>shared_ptr</code> 和 <code>weak_ptr</code>。需要注意的是 <code>unique_ptr</code>对应 <code>boost</code> 的 <code>scoped_ptr</code>。并且这些智能指针的实现原理是参考 <code>boost</code> 中的实现的</li>
</ol>
<h2 id="auto-ptr"><a href="#auto-ptr" class="headerlink" title="auto_ptr"></a>auto_ptr</h2><figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br><span class="line">40</span><br><span class="line">41</span><br><span class="line">42</span><br><span class="line">43</span><br><span class="line">44</span><br><span class="line">45</span><br><span class="line">46</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">template</span>&lt;<span class="keyword">class</span> <span class="title class_">T</span>&gt;</span><br><span class="line"><span class="keyword">class</span> <span class="title class_">auto_ptr</span></span><br><span class="line">&#123;</span><br><span class="line"><span class="keyword">public</span>:</span><br><span class="line">	<span class="comment">// RAII</span></span><br><span class="line">	<span class="comment">// 像指针一样</span></span><br><span class="line">	<span class="built_in">auto_ptr</span>(T* ptr)</span><br><span class="line">		:_ptr(ptr)</span><br><span class="line">	&#123;&#125;</span><br><span class="line"></span><br><span class="line">	~<span class="built_in">auto_ptr</span>()</span><br><span class="line">	&#123;</span><br><span class="line">		cout &lt;&lt; <span class="string">&quot;delete:&quot;</span> &lt;&lt; _ptr &lt;&lt; endl;</span><br><span class="line">		<span class="keyword">delete</span> _ptr;</span><br><span class="line">	&#125;</span><br><span class="line"></span><br><span class="line">	T&amp; <span class="keyword">operator</span>*()</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="keyword">return</span> *_ptr;</span><br><span class="line">	&#125;</span><br><span class="line"></span><br><span class="line">	T* <span class="keyword">operator</span>-&gt;()</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="keyword">return</span> _ptr;</span><br><span class="line">	&#125;</span><br><span class="line">	</span><br><span class="line">	<span class="comment">// ap3(ap1)</span></span><br><span class="line">	<span class="comment">// 管理权转移</span></span><br><span class="line">	<span class="built_in">auto_ptr</span>(auto_ptr&lt;T&gt;&amp; ap)</span><br><span class="line">		:_ptr(ap._ptr)</span><br><span class="line">	&#123;</span><br><span class="line">		ap._ptr = <span class="literal">nullptr</span>;</span><br><span class="line">	&#125;</span><br><span class="line"></span><br><span class="line">	auto_ptr&lt;T&gt;&amp; <span class="keyword">operator</span>=(auto_ptr&lt;T&gt;&amp; ap) </span><br><span class="line">	&#123;</span><br><span class="line">		<span class="keyword">if</span> (<span class="keyword">this</span> != &amp;ap) </span><br><span class="line">		&#123;</span><br><span class="line">			_ptr = ap._ptr;       <span class="comment">// 转移所有权</span></span><br><span class="line">			ap._ptr = <span class="literal">nullptr</span>;    <span class="comment">// 原指针置空</span></span><br><span class="line">		&#125;</span><br><span class="line">		<span class="keyword">return</span> *<span class="keyword">this</span>;</span><br><span class="line">	&#125;</span><br><span class="line"><span class="keyword">private</span>:</span><br><span class="line">	T* _ptr;</span><br><span class="line">&#125;;</span><br></pre></td></tr></table></figure>

<p><code>auto_ptr</code> 在 <code>C++98</code> 就已经被引入，实现了智能指针如上面所讲的最基础的功能，同时他还额外对拷贝构造、<code>=</code> 重载进行了显式调用，但是这种拷贝虽然能解决新对象的初始化，但是对于被拷贝的对象，造成了指针资源所有权被转移走，跟移动构造有些类似</p>
<p>因此，<code>auto_ptr</code> 会导致管理权转移，拷贝对象被悬空，<code>auto_ptr</code> 是一个失败设计，很多公司明确要求不能使用 <code>auto_ptr</code></p>
<h2 id="unique-ptr"><a href="#unique-ptr" class="headerlink" title="unique_ptr"></a>unique_ptr</h2><figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">template</span>&lt;<span class="keyword">class</span> <span class="title class_">T</span>&gt;</span><br><span class="line"><span class="keyword">class</span> <span class="title class_">unique_ptr</span></span><br><span class="line">&#123;</span><br><span class="line"><span class="keyword">public</span>:</span><br><span class="line">	<span class="comment">// RAII</span></span><br><span class="line">	<span class="comment">// 像指针一样</span></span><br><span class="line">	<span class="built_in">unique_ptr</span>(T* ptr)</span><br><span class="line">		:_ptr(ptr)</span><br><span class="line">	&#123;&#125;</span><br><span class="line"></span><br><span class="line">	~<span class="built_in">unique_ptr</span>()</span><br><span class="line">	&#123;</span><br><span class="line">		cout &lt;&lt; <span class="string">&quot;delete:&quot;</span> &lt;&lt; _ptr &lt;&lt; endl;</span><br><span class="line">		<span class="keyword">delete</span> _ptr;</span><br><span class="line">	&#125;</span><br><span class="line"></span><br><span class="line">	T&amp; <span class="keyword">operator</span>*()</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="keyword">return</span> *_ptr;</span><br><span class="line">	&#125;</span><br><span class="line"></span><br><span class="line">	T* <span class="keyword">operator</span>-&gt;()</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="keyword">return</span> _ptr;</span><br><span class="line">	&#125;</span><br><span class="line"></span><br><span class="line">	<span class="comment">// ap3(ap1)</span></span><br><span class="line">	<span class="comment">// 管理权转移</span></span><br><span class="line">	<span class="comment">// 防拷贝</span></span><br><span class="line">	<span class="built_in">unique_ptr</span>(unique_ptr&lt;T&gt;&amp; ap) = <span class="keyword">delete</span>;</span><br><span class="line">	unique_ptr&lt;T&gt;&amp; <span class="keyword">operator</span>=(unique_ptr&lt;T&gt;&amp; ap) = <span class="keyword">delete</span>;</span><br><span class="line"><span class="keyword">private</span>:</span><br><span class="line">	T* _ptr;</span><br><span class="line">&#125;;</span><br></pre></td></tr></table></figure>

<p><code>unique_ptr</code> 很简单粗暴，直接禁止了拷贝机制</p>
<p>因此，建议在不需要拷贝的场景使用该智能指针</p>
<h2 id="shared-ptr"><a href="#shared-ptr" class="headerlink" title="shared_ptr"></a>shared_ptr</h2><figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br><span class="line">40</span><br><span class="line">41</span><br><span class="line">42</span><br><span class="line">43</span><br><span class="line">44</span><br><span class="line">45</span><br><span class="line">46</span><br><span class="line">47</span><br><span class="line">48</span><br><span class="line">49</span><br><span class="line">50</span><br><span class="line">51</span><br><span class="line">52</span><br><span class="line">53</span><br><span class="line">54</span><br><span class="line">55</span><br><span class="line">56</span><br><span class="line">57</span><br><span class="line">58</span><br><span class="line">59</span><br><span class="line">60</span><br><span class="line">61</span><br><span class="line">62</span><br><span class="line">63</span><br><span class="line">64</span><br><span class="line">65</span><br><span class="line">66</span><br><span class="line">67</span><br><span class="line">68</span><br><span class="line">69</span><br><span class="line">70</span><br><span class="line">71</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">template</span>&lt;<span class="keyword">class</span> <span class="title class_">T</span>&gt;</span><br><span class="line"><span class="keyword">class</span> <span class="title class_">shared_ptr</span></span><br><span class="line">&#123;</span><br><span class="line"><span class="keyword">public</span>:</span><br><span class="line">	<span class="comment">// RAII</span></span><br><span class="line">	<span class="comment">// 像指针一样</span></span><br><span class="line">	<span class="built_in">shared_ptr</span>(T* ptr = <span class="literal">nullptr</span>)</span><br><span class="line">		:_ptr(ptr)</span><br><span class="line">		,_pcount(<span class="keyword">new</span> <span class="built_in">int</span>(<span class="number">1</span>))</span><br><span class="line">	&#123;&#125;</span><br><span class="line"></span><br><span class="line">	~<span class="built_in">shared_ptr</span>()</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="keyword">if</span> (--(*_pcount) == <span class="number">0</span>)</span><br><span class="line">		&#123;</span><br><span class="line">			cout &lt;&lt; <span class="string">&quot;delete:&quot;</span> &lt;&lt; _ptr &lt;&lt; endl;</span><br><span class="line">			<span class="keyword">delete</span> _ptr;</span><br><span class="line">			<span class="keyword">delete</span> _pcount;</span><br><span class="line">		&#125;</span><br><span class="line">	&#125;</span><br><span class="line"></span><br><span class="line">	T&amp; <span class="keyword">operator</span>*()</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="keyword">return</span> *_ptr;</span><br><span class="line">	&#125;</span><br><span class="line"></span><br><span class="line">	T* <span class="keyword">operator</span>-&gt;()</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="keyword">return</span> _ptr;</span><br><span class="line">	&#125;</span><br><span class="line"></span><br><span class="line">	<span class="comment">// sp3(sp1)</span></span><br><span class="line">	<span class="built_in">shared_ptr</span>(<span class="type">const</span> shared_ptr&lt;T&gt;&amp; sp)</span><br><span class="line">		:_ptr(sp._ptr)</span><br><span class="line">		,_pcount(sp._pcount)</span><br><span class="line">	&#123;</span><br><span class="line">		++(*_pcount);</span><br><span class="line">	&#125;</span><br><span class="line"></span><br><span class="line">	shared_ptr&lt;T&gt;&amp; <span class="keyword">operator</span>=(<span class="type">const</span> shared_ptr&lt;T&gt;&amp; sp)</span><br><span class="line">	&#123;</span><br><span class="line">		<span class="keyword">if</span> (_ptr == sp._ptr)</span><br><span class="line">			<span class="keyword">return</span> *<span class="keyword">this</span>;</span><br><span class="line"></span><br><span class="line">		<span class="keyword">if</span> (--(*_pcount) == <span class="number">0</span>)</span><br><span class="line">		&#123;</span><br><span class="line">			<span class="keyword">delete</span> _ptr;</span><br><span class="line">			<span class="keyword">delete</span> _pcount;</span><br><span class="line">		&#125;</span><br><span class="line"></span><br><span class="line">		_ptr = sp._ptr;</span><br><span class="line">		_pcount = sp._pcount;</span><br><span class="line">		++(*_pcount);</span><br><span class="line"></span><br><span class="line">		<span class="keyword">return</span> *<span class="keyword">this</span>;</span><br><span class="line">	&#125;</span><br><span class="line"></span><br><span class="line">	<span class="function"><span class="type">int</span> <span class="title">use_count</span><span class="params">()</span> <span class="type">const</span></span></span><br><span class="line"><span class="function">	</span>&#123;</span><br><span class="line">		<span class="keyword">return</span> *_pcount;</span><br><span class="line">	&#125;</span><br><span class="line"></span><br><span class="line">	<span class="function">T* <span class="title">get</span><span class="params">()</span> <span class="type">const</span></span></span><br><span class="line"><span class="function">	</span>&#123;</span><br><span class="line">		<span class="keyword">return</span> _ptr;</span><br><span class="line">	&#125;</span><br><span class="line"></span><br><span class="line"><span class="keyword">private</span>:</span><br><span class="line">	T* _ptr;</span><br><span class="line">	<span class="type">int</span>* _pcount;</span><br><span class="line">&#125;;</span><br></pre></td></tr></table></figure>

<p><code>C++11</code> 中的智能指针就属 <code>shared_ptr</code> 使用的最多，因为它解决了赋值造成的资源被转移可能会被错误访问的问题</p>
<p>类中增加一个新的指针 <code>_pcount</code> 用于计数，即计数有多少个 <code>_ptr</code> 指向同一片空间，多个 <code>shared_ptr</code> 可以同时指向同一个对象，每次创建新的 <code>shared_ptr</code> 指向该对象，引用计数加  <code>1</code>；每次 <code>shared_ptr</code> 析构或者被赋值为指向其他对象，引用计数减  <code>1</code>。当最后一个指向该对象的 <code>shared_ptr</code> 析构时，对象会被自动删除，从而避免内存泄漏</p>
<p>🔥<strong>值得注意的是：</strong> <code>shared_ptr</code> 同时也支持了无法自己给自己赋值，这里还涉及一些关于线程安全的知识点，待 <code>Linux</code> 学习过后再来补充</p>
<h2 id="weak-ptr"><a href="#weak-ptr" class="headerlink" title="weak_ptr"></a>weak_ptr</h2><p>看似完美的 <code>shared_ptr</code> 其实也会有疏漏，比如：引用循环</p>
<figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">struct</span> <span class="title class_">ListNode</span></span><br><span class="line">&#123;</span><br><span class="line">	<span class="type">int</span> _data;</span><br><span class="line">	shared_ptr&lt;ListNode&gt; _next;</span><br><span class="line">	shared_ptr&lt;ListNode&gt; _prev;</span><br><span class="line">&#125;;</span><br><span class="line"><span class="function"><span class="type">int</span> <span class="title">main</span><span class="params">()</span></span></span><br><span class="line"><span class="function"></span>&#123;</span><br><span class="line">	<span class="function">shared_ptr&lt;ListNode&gt; <span class="title">node1</span><span class="params">(<span class="keyword">new</span> ListNode)</span></span>;</span><br><span class="line">	<span class="function">shared_ptr&lt;ListNode&gt; <span class="title">node2</span><span class="params">(<span class="keyword">new</span> ListNode)</span></span>;</span><br><span class="line">	cout &lt;&lt; node<span class="number">1.</span><span class="built_in">use_count</span>() &lt;&lt; endl;</span><br><span class="line">	cout &lt;&lt; node<span class="number">2.</span><span class="built_in">use_count</span>() &lt;&lt; endl;</span><br><span class="line">	node1-&gt;_next = node2;</span><br><span class="line">	node2-&gt;_prev = node1;</span><br><span class="line">	cout &lt;&lt; node<span class="number">1.</span><span class="built_in">use_count</span>() &lt;&lt; endl;</span><br><span class="line">	cout &lt;&lt; node<span class="number">2.</span><span class="built_in">use_count</span>() &lt;&lt; endl;</span><br><span class="line">	<span class="keyword">return</span> <span class="number">0</span>;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>

<p>当执行 <code>node1-&gt;next = node2</code> 和 <code>node2-&gt;prev = node1</code> 时，<code>node1</code> 内部的 <code>_next</code> 指针指向 <code>node2</code> ，<code>node2</code> 内部的 <code>_prev</code> 指针指向 <code>node1</code> 。这就导致两个节点之间形成了循环引用关系。此时，由于互相引用，每个节点的引用计数都变为 <code>2</code> ，因为除了外部的智能指针引用，还多了来自另一个节点内部指针的引用</p>
<p>当 <code>node1</code> 和 <code>node2</code> 智能指针对象离开作用域开始析构时，它们首先会将所指向节点的引用计数减 <code>1</code> 。此时，每个节点的引用计数变为 <code>1</code> ，而不是预期的 <code>0</code> 。这是因为 <code>node1</code> 的 <code>_next</code> 还指向 <code>node2</code> ，<code>node2</code> 的 <code>_prev</code> 还指向 <code>node1</code> ，使得它们的引用计数无法归零</p>
<p>对于 <code>shared_ptr</code> 来说，只有当引用计数变为 <code>0</code> 时才会释放所管理的资源。由于这种循环引用的存在，<code>node1</code> 等待 <code>node2</code> 先释放（因为 <code>node2</code> 的 <code>_prev</code> 引用着 <code>node1</code> ），而 <code>node2</code> 又等待 <code>node1</code> 先释放（因为 <code>node1</code> 的 <code>_next</code> 引用着 <code>node2</code> ），最终导致这两个节点所占用的资源都无法被释放，造成内存泄漏</p>
<figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">class</span> <span class="title class_">ListNode</span> </span><br><span class="line">&#123;</span><br><span class="line"><span class="keyword">public</span>:</span><br><span class="line">    weak_ptr&lt;ListNode&gt; _next; </span><br><span class="line">    weak_ptr&lt;ListNode&gt; _prev;</span><br><span class="line">&#125;;</span><br></pre></td></tr></table></figure>

<p>为了解决 <code>shared_ptr</code> 的循环引用问题，通常可以使用 <code>weak_ptr</code> 。<code>weak_ptr</code> 是一种弱引用智能指针，它不会增加所指向对象的引用计数。将循环引用中的某一个引用（比如 <code>ListNode</code> 类中的 <code>_prev</code> 或 <code>_next</code> 其中之一）改为 <code>weak_ptr</code> 类型，就可以打破循环引用</p>
<p>因此，<code>weak_ptr</code> 是一种专门解决循环引用问题的指针</p>
<h1 id="删除器"><a href="#删除器" class="headerlink" title="删除器"></a>删除器</h1><figure class="highlight cpp"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br><span class="line">40</span><br><span class="line">41</span><br><span class="line">42</span><br><span class="line">43</span><br><span class="line">44</span><br><span class="line">45</span><br><span class="line">46</span><br><span class="line">47</span><br><span class="line">48</span><br><span class="line">49</span><br><span class="line">50</span><br><span class="line">51</span><br><span class="line">52</span><br><span class="line">53</span><br><span class="line">54</span><br><span class="line">55</span><br><span class="line">56</span><br><span class="line">57</span><br><span class="line">58</span><br><span class="line">59</span><br><span class="line">60</span><br><span class="line">61</span><br><span class="line">62</span><br><span class="line">63</span><br><span class="line">64</span><br><span class="line">65</span><br><span class="line">66</span><br><span class="line">67</span><br><span class="line">68</span><br><span class="line">69</span><br><span class="line">70</span><br><span class="line">71</span><br><span class="line">72</span><br><span class="line">73</span><br><span class="line">74</span><br><span class="line">75</span><br><span class="line">76</span><br><span class="line">77</span><br><span class="line">78</span><br><span class="line">79</span><br><span class="line">80</span><br><span class="line">81</span><br><span class="line">82</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">#<span class="keyword">include</span> <span class="string">&lt;iostream&gt;</span></span></span><br><span class="line"><span class="meta">#<span class="keyword">include</span> <span class="string">&lt;memory&gt;</span></span></span><br><span class="line"><span class="meta">#<span class="keyword">include</span> <span class="string">&lt;string&gt;</span></span></span><br><span class="line"></span><br><span class="line"><span class="keyword">using</span> <span class="keyword">namespace</span> std;</span><br><span class="line"></span><br><span class="line"><span class="keyword">class</span> <span class="title class_">A</span> </span><br><span class="line">&#123;</span><br><span class="line"><span class="keyword">public</span>:</span><br><span class="line">    ~<span class="built_in">A</span>() </span><br><span class="line">    &#123; </span><br><span class="line">        cout &lt;&lt; <span class="string">&quot;A::~A()&quot;</span> &lt;&lt; endl; </span><br><span class="line">    &#125;</span><br><span class="line">&#125;;</span><br><span class="line"></span><br><span class="line"><span class="comment">// 仿函数删除器：用于释放malloc分配的内存</span></span><br><span class="line"><span class="keyword">template</span>&lt;<span class="keyword">class</span> <span class="title class_">T</span>&gt;</span><br><span class="line"><span class="keyword">struct</span> <span class="title class_">FreeFunc</span> </span><br><span class="line">&#123;</span><br><span class="line">    <span class="function"><span class="type">void</span> <span class="title">operator</span><span class="params">()</span><span class="params">(T* ptr)</span> <span class="type">const</span> </span></span><br><span class="line"><span class="function">    </span>&#123;</span><br><span class="line">        cout &lt;&lt; <span class="string">&quot;FreeFunc: free memory at &quot;</span> &lt;&lt; ptr &lt;&lt; endl;</span><br><span class="line">        <span class="built_in">free</span>(ptr);</span><br><span class="line">    &#125;</span><br><span class="line">&#125;;</span><br><span class="line"></span><br><span class="line"><span class="comment">// 仿函数删除器：用于释放数组</span></span><br><span class="line"><span class="keyword">template</span>&lt;<span class="keyword">class</span> <span class="title class_">T</span>&gt;</span><br><span class="line"><span class="keyword">struct</span> <span class="title class_">DeleteArrayFunc</span> </span><br><span class="line">&#123;</span><br><span class="line">    <span class="function"><span class="type">void</span> <span class="title">operator</span><span class="params">()</span><span class="params">(T* ptr)</span> <span class="type">const</span> </span></span><br><span class="line"><span class="function">    </span>&#123;</span><br><span class="line">        cout &lt;&lt; <span class="string">&quot;DeleteArrayFunc: delete[] memory at &quot;</span> &lt;&lt; ptr &lt;&lt; endl;</span><br><span class="line">        <span class="keyword">delete</span>[] ptr;</span><br><span class="line">    &#125;</span><br><span class="line">&#125;;</span><br><span class="line"></span><br><span class="line"><span class="function"><span class="type">int</span> <span class="title">main</span><span class="params">()</span> </span></span><br><span class="line"><span class="function"></span>&#123;</span><br><span class="line">    <span class="comment">// 使用FreeFunc删除器的shared_ptr</span></span><br><span class="line">    <span class="function">shared_ptr&lt;<span class="type">int</span>&gt; <span class="title">sp1</span><span class="params">((<span class="type">int</span>*)malloc(<span class="keyword">sizeof</span>(<span class="type">int</span>)), FreeFunc&lt;<span class="type">int</span>&gt;())</span></span>;</span><br><span class="line">    *sp1 = <span class="number">100</span>;</span><br><span class="line">    cout &lt;&lt; <span class="string">&quot;sp1: &quot;</span> &lt;&lt; *sp1 &lt;&lt; <span class="string">&quot; at &quot;</span> &lt;&lt; sp<span class="number">1.</span><span class="built_in">get</span>() &lt;&lt; endl;</span><br><span class="line">    <span class="comment">// 离开作用域时调用FreeFunc删除器</span></span><br><span class="line"></span><br><span class="line">    <span class="comment">// 使用DeleteArrayFunc删除器的shared_ptr</span></span><br><span class="line">    <span class="function">shared_ptr&lt;<span class="type">int</span>&gt; <span class="title">sp2</span><span class="params">(<span class="keyword">new</span> <span class="type">int</span>[<span class="number">5</span>], DeleteArrayFunc&lt;<span class="type">int</span>&gt;())</span></span>;</span><br><span class="line">    <span class="keyword">for</span> (<span class="type">int</span> i = <span class="number">0</span>; i &lt; <span class="number">5</span>; ++i) &#123;</span><br><span class="line">        sp<span class="number">2.</span><span class="built_in">get</span>()[i] = i;</span><br><span class="line">    &#125;</span><br><span class="line">    cout &lt;&lt; <span class="string">&quot;sp2 array:&quot;</span>;</span><br><span class="line">    <span class="keyword">for</span> (<span class="type">int</span> i = <span class="number">0</span>; i &lt; <span class="number">5</span>; ++i) &#123;</span><br><span class="line">        cout &lt;&lt; <span class="string">&quot; &quot;</span> &lt;&lt; sp<span class="number">2.</span><span class="built_in">get</span>()[i];</span><br><span class="line">    &#125;</span><br><span class="line">    cout &lt;&lt; endl;</span><br><span class="line">    <span class="comment">// 离开作用域时调用DeleteArrayFunc删除器</span></span><br><span class="line"></span><br><span class="line">    <span class="comment">// 使用lambda删除器管理A对象数组</span></span><br><span class="line">    <span class="function">shared_ptr&lt;A&gt; <span class="title">sp4</span><span class="params">(<span class="keyword">new</span> A[<span class="number">3</span>], [](A* p) &#123;</span></span></span><br><span class="line"><span class="params"><span class="function">        cout &lt;&lt; <span class="string">&quot;Lambda: deleting array at &quot;</span> &lt;&lt; p &lt;&lt; endl;</span></span></span><br><span class="line"><span class="params"><span class="function">        <span class="keyword">delete</span>[] p;</span></span></span><br><span class="line"><span class="params"><span class="function">        &#125;)</span></span>;</span><br><span class="line">    cout &lt;&lt; <span class="string">&quot;sp4 array of A objects created&quot;</span> &lt;&lt; endl;</span><br><span class="line">    <span class="comment">// 离开作用域时调用lambda删除器</span></span><br><span class="line"></span><br><span class="line">    <span class="comment">// 使用lambda删除器管理文件句柄</span></span><br><span class="line">    <span class="function">shared_ptr&lt;FILE&gt; <span class="title">sp5</span><span class="params">(fopen(<span class="string">&quot;test.txt&quot;</span>, <span class="string">&quot;w&quot;</span>), [](FILE* p) &#123;</span></span></span><br><span class="line"><span class="params"><span class="function">    <span class="keyword">if</span> (p) </span></span></span><br><span class="line"><span class="params"><span class="function">    &#123;</span></span></span><br><span class="line"><span class="params"><span class="function">        cout &lt;&lt; <span class="string">&quot;Lambda: closing file&quot;</span> &lt;&lt; endl;</span></span></span><br><span class="line"><span class="params"><span class="function">        fclose(p);</span></span></span><br><span class="line"><span class="params"><span class="function">    &#125;</span></span></span><br><span class="line"><span class="params"><span class="function">    &#125;)</span></span>;</span><br><span class="line">    <span class="keyword">if</span> (sp5) </span><br><span class="line">    &#123;</span><br><span class="line">        <span class="built_in">fprintf</span>(sp<span class="number">5.</span><span class="built_in">get</span>(), <span class="string">&quot;Hello, shared_ptr with deleter!\n&quot;</span>);</span><br><span class="line">        cout &lt;&lt; <span class="string">&quot;File written&quot;</span> &lt;&lt; endl;</span><br><span class="line">    &#125;</span><br><span class="line">    <span class="comment">// 离开作用域时调用lambda删除器关闭文件</span></span><br><span class="line"></span><br><span class="line">    <span class="keyword">return</span> <span class="number">0</span>;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>

<p>对于所有的指针不一定是 <code>new</code> 出来的对象，因此利用仿函数设置了删除器，这样就可以调用对应的删除</p>
<hr>
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id="card-toc"><div class="item-headline"><i class="fas fa-stream"></i><span>目录</span><span class="toc-percentage"></span></div><div class="toc-content"><ol class="toc"><li class="toc-item toc-level-1"><a class="toc-link" href="#%E4%B8%BA%E4%BB%80%E4%B9%88%E9%9C%80%E8%A6%81%E6%99%BA%E8%83%BD%E6%8C%87%E9%92%88%EF%BC%9F"><span class="toc-number">1.</span> <span class="toc-text">为什么需要智能指针？</span></a></li><li class="toc-item toc-level-1"><a class="toc-link" href="#%E6%99%BA%E8%83%BD%E6%8C%87%E9%92%88%E5%8E%9F%E7%90%86"><span class="toc-number">2.</span> <span class="toc-text">智能指针原理</span></a><ol class="toc-child"><li class="toc-item toc-level-2"><a class="toc-link" href="#RAll"><span class="toc-number">2.1.</span> <span class="toc-text">RAll</span></a></li><li class="toc-item toc-level-2"><a class="toc-link" href="#%E5%83%8F%E6%8C%87%E9%92%88%E4%B8%80%E6%A0%B7%E4%BD%BF%E7%94%A8"><span class="toc-number">2.2.</span> <span class="toc-text">像指针一样使用</span></a></li></ol></li><li class="toc-item toc-level-1"><a class="toc-link" href="#C-11%E7%9A%84%E6%99%BA%E8%83%BD%E6%8C%87%E9%92%88"><span class="toc-number">3.</span> <span class="toc-text">C++11的智能指针</span></a><ol class="toc-child"><li class="toc-item toc-level-2"><a class="toc-link" href="#auto-ptr"><span class="toc-number">3.1.</span> <span class="toc-text">auto_ptr</span></a></li><li class="toc-item toc-level-2"><a class="toc-link" href="#unique-ptr"><span class="toc-number">3.2.</span> <span class="toc-text">unique_ptr</span></a></li><li class="toc-item toc-level-2"><a class="toc-link" href="#shared-ptr"><span class="toc-number">3.3.</span> <span class="toc-text">shared_ptr</span></a></li><li class="toc-item toc-level-2"><a class="toc-link" href="#weak-ptr"><span class="toc-number">3.4.</span> <span class="toc-text">weak_ptr</span></a></li></ol></li><li class="toc-item toc-level-1"><a class="toc-link" href="#%E5%88%A0%E9%99%A4%E5%99%A8"><span class="toc-number">4.</span> <span class="toc-text">删除器</span></a></li><li class="toc-item toc-level-1"><a class="toc-link" href="#%E5%B8%8C%E6%9C%9B%E8%AF%BB%E8%80%85%E4%BB%AC%E5%A4%9A%E5%A4%9A%E4%B8%89%E8%BF%9E%E6%94%AF%E6%8C%81"><span class="toc-number">5.</span> <span class="toc-text">希望读者们多多三连支持</span></a></li><li class="toc-item toc-level-1"><a class="toc-link" href="#%E5%B0%8F%E7%BC%96%E4%BC%9A%E7%BB%A7%E7%BB%AD%E6%9B%B4%E6%96%B0"><span class="toc-number">6.</span> <span class="toc-text">小编会继续更新</span></a></li><li class="toc-item toc-level-1"><a class="toc-link" href="#%E4%BD%A0%E4%BB%AC%E7%9A%84%E9%BC%93%E5%8A%B1%E5%B0%B1%E6%98%AF%E6%88%91%E5%89%8D%E8%BF%9B%E7%9A%84%E5%8A%A8%E5%8A%9B%EF%BC%81"><span class="toc-number">7.</span> <span class="toc-text">你们的鼓励就是我前进的动力！</span></a></li></ol></div></div><div class="card-widget card-recent-post"><div class="item-headline"><i class="fas fa-history"></i><span>最新文章</span></div><div class="aside-list"><div class="aside-list-item"><a class="thumbnail" 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